Raman spectra of biological membranes are very rich in detail and potentially highly informative. However, the full potential of Raman spectroscopy as applied to biological systems has yet to be realized. Our approach to the analysis of the highly complex and variable spectra involves several routes. First, it was necessary to establish experimental methods for erthyltrocyte membranes that are capable of yielding definite reproducible results; the spectra obtained exhibited greater variability and sensitivity than originally anticipated. The erythrocyte membrane is well suited for these studies since it may be systematically varied by biochemical dissection and structurally modified in a controlled manner in order to extract detailed information from the spectra. In addition, complimentary model membrane studies are in progress which allow molecular ordering and lipid protein interactions to be observed in highly controlled systems. By combining these approaches, we plan to clarify and develop the application of Raman spectroscopy to biological membranes and to extend its use to the study of disease states.